The HP 816651-L21 (816651-L21 - HP 2.10GHz 8GT/s QPI 40MB Cache Socket FCLGA2011 Intel Xeon E7-4850 v4 16-Core Processor for ProLiant DL580 G9) is a Intel Unboxed Processors component engineered for sustained enterprise-class workloads. This part addresses common procurement scenarios where exact-match replacement, capacity expansion, or new-build deployment is required. Technical specifications include clock speed of 2.10 GHz, bus speed of 8 GT/s, cache of 40MB, socket of FCLGA2011, generation of Gen9. Typical use cases include data-center server fleet refresh, replacement of dead-on-arrival CPUs under existing service contracts, second-socket population on partially-populated dual-socket boards, and lab/test rebuild programs. Pro Disk Network supplies the 816651-L21 to US business buyers. Stocked units ship same-day on in-stock orders placed before 3pm ET. Pro Disk Network applies a 90-day functional warranty. Free US ground shipping on orders over $150; same-day expedited (UPS Next Day Air, FedEx Priority) available at checkout.
The 816651-L21 is a HP intel unboxed processors component with clock speed 2.10 GHz, bus speed 8 GT/s, cache 40MB. Pricing on the 816651-L21 is quote-based — email sales@prodisknetwork.com or use our live chat for a quote within one business day.
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Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the 816651-L21 are shown on this page.
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Same-Day US Shipping — orders before 3pm ET ship today via UPS
30-Day Returns — pre-paid label on DOA and defective items
Quick Answer: What socket does the 816651-L21 use?
Confirm the socket against your motherboard's CPU support list - Intel Xeon Scalable spans LGA 3647 (1st/2nd gen), LGA 4189 (3rd gen Ice Lake), and LGA 4677 (4th/5th gen Sapphire/Emerald Rapids). A BIOS update is often required for newer steppings even on the same socket. Email sales@prodisknetwork.com with your motherboard model for a compatibility check.
How fast does the 816651-L21 ship?
816651-L21 orders placed before 3 pm ET ship the same business day from US warehouses. Delivery is next business day to most metro ZIPs via FedEx/UPS overnight; ground delivery covers remaining US in 1-4 business days.
The 816651-L21 is deployed by US enterprises, MSPs, government, and education customers across multiple infrastructure scenarios. Below are the most common deployment patterns Pro Disk Network sees in real-world orders.
Hyper-V Cluster Node — Windows Server Datacenter licenses by core, but Hyper-V scales linearly. Higher-clock, mid-core SKUs win for transactional workloads.
Citrix VDI Pool — Frequency-sensitive — prefer high-clock 16–18 core SKUs over high-core-count parts to maintain user-perceived snappiness.
Kubernetes / Tanzu Workers — Higher core count amortises better across many small Pods. EVC mode planning matters for live-migrate parity.
AI Inference Host — Sapphire Rapids and Emerald Rapids include AMX silicon for INT8 inference acceleration — meaningful uplift for BERT, ResNet, and LLM serving.
What is the 816651-L21?
The 816651-L21 is a HP server-class processor with clock speed 2.10 GHz and bus speed 8 GT/s, manufactured by HP. Pro Disk Network ships this part new and certified-refurbished from our US warehouse with same-day dispatch on orders placed before 3 PM ET, backed by a 30-day return guarantee.
Pros & Cons of 816651-L21
Pros
Same-day shipping from our US warehouse cuts deployment lead time
Cons
Older socket family — confirm motherboard compatibility
BIOS update typically required for newer CPU steppings
Not a fit for desktop platforms — these are server SKUs
Frequently Asked Questions about 816651-L21
Is the 816651-L21 a genuine HP part?
Yes. Pro Disk Network sources every 816651-L21 as factory-original HP inventory. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned HP servers, surface-tested, and re-warranted by Pro Disk Network for 90 days.
What socket does the 816651-L21 use?
Confirm the socket against your motherboard's CPU support list - Intel Xeon Scalable spans LGA 3647 (1st/2nd gen), LGA 4189 (3rd gen Ice Lake), and LGA 4677 (4th/5th gen Sapphire/Emerald Rapids). A BIOS update is often required for newer steppings even on the same socket. Email sales@prodisknetwork.com with your motherboard model for a compatibility check.
How fast does the 816651-L21 ship?
816651-L21 orders placed before 3 pm ET ship the same business day from US warehouses. Delivery is next business day to most metro ZIPs via FedEx/UPS overnight; ground delivery covers remaining US in 1-4 business days.
What is the warranty on the 816651-L21?
New 816651-L21 units carry the full HP manufacturer warranty (typically 1 to 5 years depending on product line). Refurbished and bulk-OEM units include a Pro Disk Network advance-replacement warranty (90 days refurbished). DOA replacement is free within 30 days of receipt.
Do you offer bulk pricing for the 816651-L21?
Email sales@prodisknetwork.com with the quantity and target ship date for a quote within one business day.
Pro Disk Network Buyer’s Guide: Intel Unboxed Processors
Socket Compatibility, EVC Mode, and BIOS Revision Planning
For VMware vSphere clusters, EVC (Enhanced vMotion Compatibility) mode dictates which CPU generations can coexist in the same cluster while still supporting live migration. Adding a newer-generation 816651-L21 to a cluster with older CPUs requires setting EVC to the older baseline, which disables newer instructions on the new CPU. Plan EVC mode at cluster creation time; changing it later requires powering off the cluster.
AI Workloads, AMX, and the Inference Performance Story
Plan memory bandwidth alongside the CPU: AMX inference is memory-bandwidth sensitive. A 816651-L21 paired with insufficient memory channels (e.g., DDR5-4800 in fewer than 8 channels per socket) will underperform its theoretical peak by 30-40%. Confirm motherboard channel count and DIMM population before ordering.